Engines may utilize recirculation of exhaust gas from an engine exhaust system to an engine intake system, a process referred to as exhaust gas recirculation (EGR), to reduce regulated emissions. An EGR system may include an EGR cooler to cool the exhaust gas before it enters the intake system. In some examples, the EGR cooler and the engine may be coupled in parallel in a cooling fluid circuit. In such an example, however, an amount of cooling fluid may be increased and/or a flow rate of the cooling fluid may be doubled, for example, as similar flow rates of cooling fluid are sent through the engine and the EGR cooler. In other examples, the EGR cooler may be positioned downstream of the engine in the cooling circuit. As such, an engine operating temperature may be reduced due to cooler cooling fluid flowing through the engine, thereby reducing a thermal efficiency of the engine. Further, the cooling circuit may be pressurized in order to maintain the cooling fluid under its boiling point. In this case, degradation of a pressure cap may lead to engine or EGR cooler failure.